Combustion devices—such as furnaces and boilers—typically generate heat by burning a fuel-air mixture. To maintain the combustion reaction, a requisite amount of fuel and air must be supplied to a chamber, where it is ignited to produce heat. The amount of fuel that is burned in this reaction is dependent on a variety of factors, including the ignition and the flow rate of fuel and air, among other factors. Because combustion reactions involve a proper balance of input fuel, air, and ignition, sustaining these reactions can be a difficult task. Furthermore, the efficiency of a combustion reaction can be diminished if the ratio of fuel and air are not optimal for a given system and/or application.
Additionally, certain conditions within a combustion system can cause significant failures that are potentially dangerous or damaging to the device. For example, if the flow rate of fuel-air mixture into a chamber is too slow, an ignited fuel-air flame can travel “back” or upstream toward the fuel-air source. One way to address this problem involves placing a flame arrestor between the fuel-air source and the place of combustion to prevent any flame from traveling “upstream.” While effective at improving the safety of a combustion device, flame arrestors often emit turbulent and stirred up fuel-air mixtures that results in an unstable flame. It is accordingly an objective of the present disclosure to provide a combustion device with an improved burner nozzle that incorporates a flame arrestor and that produces a stable flame.
Some combustion devices, such as boilers, involve heating water or another medium to a desired temperature. An example operation for a boiler involves initially heating water to a boiling point, and then maintaining the temperature of the water at or near that boiling point. Because the initial heating stage requires a greater amount of energy than maintaining already-heated water, a burner that operates in a single modality can be inefficient. If combustion is very hot, water can be heated quickly, but maintaining the water at a boiling temperature is inefficient. Conversely, if combustion is mild, water is initially heated very slowly, while maintaining the water at a desired temperature is more efficient. It is accordingly another objective of the present disclosure to provide a combustion device that can modulate across varying levels of combustion.